CALLANDER, J Graham; GRANT, Walter G. A Long, Stalled Cairn, the Knowe of Yarso, in Rousay, Orkney. Proceedings of the Society of Antiquaries of Scotland, [S. l.], v. 69, p. 325–351, 1935. DOI: 10.9750/PSAS.069.325.351. Disponível em: https://journals.socantscot.org/index.php/psas/article/view/7945. Acesso em: 3 may. 2024.